Degradation of tRNAs in HeLa cells treated with heat stress or 5-FU.

<p>(A) Northern blot analysis of tRNA(Val^AAC), tRNA(iMet), tRNA(eMet), and 5S rRNA. NSUN2 and METTL1 knockdown cells and control vector-transfected cells were treated with 37°C (control), 43°C (heat stress), or 5-FU (7.69 mM) for indicated time. Total RNA (20 µg) was loaded and blotted. (B) Degradation profile of tRNA(Val^AAC), tRNA(iMet), and tRNA(eMet) in NSUN2 and METTL1 knockdown cells (closed symbols) and control vector-transfected cells (open symbols). The cells were treated with 37°C (<i>circle</i>), 43°C (<i>triangle</i>), and 5-FU (<i>square</i>). 5S rRNA transcribed by RNA polymerase III was used as a control, and quantitative data were indicated.